The Group 5A (15) elements can form molecules or ions that involve three, five, or six covalent bonds; NH₃, AsCl₅, and PF₆^- are examples. Draw the Lewis structure for each of these substances, and predict the molecular structure and hybridization for each. Why doesn’t NF₅ or NCl₆^- form?

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Group 5A (15) Elements › Elements show a wide variety of chemical properties > Nitrogen and phosphorus are nonmetals > Antimony and bismuth tend to be metallic, although no ionic compounds containing Sb³+ and Bis+ are known; the compounds containing Sb(V) and Bi(V) are molecular rather than ionic > All group members except N form molecules with five covalent bonds > The ability to form 7 bonds decreases dramatically after N › Chemistry of nitrogen > Most nitrogen-containing compounds decompose exothermically, forming the very stable N₂ molecule, which explains the power of nitrogen-based explosives > The nitrogen cycle, which consists of a series of steps, shows how nitrogen is cycled in the natural environment > Nitrogen fixation changes the N₂ in air into compounds useful to plants > The Haber process is a synthetic method of nitrogen fixation > In the natural world, nitrogen fixation occurs through nitrogen-fixing bacteria in the root nodules of certain plants and through lightning in the atmosphere > Ammonia is the most important hydride of nitrogen > Contains pyramidal NH, molecules > Widely used as a fertilizer > Hydrazine (N₂H₂) is a powerful reducing agent > Nitrogen forms a series of oxides including N₂O, NO, NO₂, and N₂Os > Nitric acid (HNO₂) is a very important strong acid manufactured by the Ostwald process › Chemistry of phosphorus > Exists in three elemental forms: white (contains P, molecules), red, and black > Phosphine (PH₂) has bond angles close to 90 degrees > Phosphorus forms oxides including P,O, and P4O₁0 (which dissolves in water to form phosphoric acid, H,PO₂)